VFIO no-iommu

[Thomas Monjalon <thomas.monjalon@6wind.com>]

Recently there were some discussions to have an upstream replacement
for our igb_uio module.
Several solutions were discussed (new uio driver, uio_pci_generic, vfio):
	https://lkml.org/lkml/2015/10/16/700

Alex Williamson (maintainer of VFIO driver), submitted a solution
and was waiting some feedback. Unfortunately, nobody caught it and
he has reverted his work:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=ae5515d

It is an important challenge to remove our out-of-tree modules and
especially igb_uio. It is a long way to have a standard solution integrated
in every distributions.
The current cooking Linux kernel is 4.4 and will have a long term maintenance:
	https://kernel.org/releases.html
So it is a pity to miss this opportunity.

Stephen has fixed a bug to use the IOMMU group zero:
	http://dpdk.org/browse/dpdk/commit/?id=22215f141b1

Is there someone interested to work on VFIO no-iommu and provide
some feedbacks?
We also need to prepare a documentation patch to explain its usage
compared to the standard VFIO mode.

Thanks